1. Field of the Invention
The present invention relates to an observation apparatus for visualizing the temporal fluctuations of the oxygen concentration distribution along the boundary of the bottom sludge and the bottom water on the seabed for observation.
2. Description of the Related Art
The dissolved oxygen level on the surface of the bottom sludge on the seabed takes a vital role for maintaining a sound ecosystem on the seabed. Known techniques for looking into the dissolved oxygen level on the surface of the bottom sludge include one with which a container having an oxygen concentration measuring chamber with an oxygen electrode, which is also called a bulging chamber, is dropped to the seabed of an observation site to measure the fall, if any, in the oxygen concentration level at the site.
JP-A-2007-120992 discloses a seabed oxygen concentration measuring apparatus having an oxygen concentration measuring chamber formed by arranging a transparent disk on a plurality of pillars standing on a construction frame so as to make the transparent disk operate as top plate of the oxygen concentration  measuring chamber and fitting an optical dissolved oxygen meter for measuring the dissolved oxygen level in the oxygen concentration measuring chamber and an agitation device for agitating the internal air of the chamber to the transparent disk.